Apparatus for back tacking loose ends of sewing machine stitching, and the like



Dec. 5, 1967 w. F. SOUTHWELL ETAL 3,356,054

' APPARATUS FOR BACK TACKING LOOSE ENDS 0F SEWING MACHINE STI-TCHING,AND THE LIKE Filed April 20, 1965 3 Sheets-Sheet l MIMI.

INVENTORS:

Dec. 5, 1967 w. F. sOUTHWELL ETAL 3,356,054

' APPARATUS FOR BACK TACKING LOOSE ENDS OF SEWING MACHINE STITCHING, ANDTHE LIKE Filed April 20, 1965. 3 Sheets-Sheet 2 Dec. 5, 1967 w. F.SOUTHWELL ETAL 3,356,054

' APPARATUS FOR BACK TACKING LOOSE ENDS OF SEWI MACHINE STITCHING ANDTHE LIKE 3 sheets sheet 5 Filed April 20, 1965 I /Z7 66 A2761 6 5 cs5 I(E6 TD mum/ W i c5A ATTORN Y5.

United States Patent 3,356,054 APPARATUS FOR BACK TACKING LOOSE ENDS OFSEWING MACHINE STITCHENG, AND THE LIKE Wyndham F. Southwell, Wilkesboro,and Nicholas Wehrmann, North Wilkeshoro, N.C., assignors of L & LManufacturing, Inc., a corporation of Delaware Filed Apr. 20, 1965, Ser.No. 449,418 8 Claims. (Cl. 112-252) Many types of sewing machines,including trimming and overedging machines, are arranged to operate evenat times when no fabric or other material is under the foot of thesewing machine. In such cases stitching tends to be formed, as bychaining off, prior to the sewing of scams or other stitches in thefabric, and this prior stitching remains as a loose end which isunsightly and which may tend to ravel. In order to prevent thisunsightliness and/or the raveling thereof, this stitching needs to becaught into the fabric stitches before its free end is cut Oil. Whilesuch a loose end may be swung back manual- 1y into the part of a seam orother line of stitching to be formed in a fabric (for example a seamjoining two pieces of fabric) that is a difficult operation to performmanually and is an exceedingly diflicult one to carry out with anydegree of uniformity in successive pieces of fabric. In this connectionit should be borne in mind that excessive looseness and excessive lengthbetween the point where the loose end meets the fabric and the pointwhere it is back-tacked to the fabric is undesirable in the finishedstitching. Lack of uniformity in the operation not only is undesirablein itself, but also results in various undesir able conditions in acertain proportion of the (joined or single) fabric pieces, or othermaterial being sewn.

With the foregoing and other considerations in view, the presentinvention contemplates the provision of looseend pulling means (morespecifically suction means) for catching up a loose end and carrying italong a course which, after sewing has started on a piece of material sothat a thread extends upwardly therefrom, moves around the thread andcrosses the intended course of seaming or other sewing on fabric piecesor other material to be sewn. Of importance in many instances is theholding of the loose end at a controlled and/or generally uniform degreeof tautness while it is swung back and back tacked and, commonly, alsocut.

Whereas, under manual operation, the back tacking step for the seamingof a ten-inch fabric portion may often consume up to 40% to 45% of thetime of each seaming operation, the present invention permits the backtacking step to be performed in only to of the time required for eachseaming operation, and in a much more uniform, accurate, and effectivemanner.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts, which will beexemplified in the constructions hereinafter set forth and the scope ofthe application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings in which:

FIGURE 1 is a fragmental top View of one form of device embodying theinvention;

FIG. 2 is a front view thereof, partly in section and showing theswinging arm in a partially-swung position;

FIG. 3 is a detail view of the lower end of the swinging arm on anenlarged scale; 7

FIG. 4 is a diagrammatic view of the swinging arm, a loose end, and apartially-sewn fabric, at the time of the initiation of the swing of theswinging arm;

FIG. 5 is a similar view showing an intermediate stage in the rearwardmovement of the swinging arm;

FIG. 6 is a similar view showing the swinging arm at the end of itsrearward movement;

FIG. 7 is a similar view showing the elements after the fabric hasresumed its forward movement, the sewing machine resumed sewing, thecutter brought into operation, and the swinging arm ready to start itsforward movement;

FIG. 8 is a perspective view on a larger scale showing the fabric afterthe loose end has been automatically caught and has been cut, and whenthe trim is in the process of being cut; and

FIG. 9 is a circuit diagram.

The exemplified apparatus comprises a conveyor 14) for carrying a pairof overlying pieces 11 and 12 of fabric (knitted fabric pieces to beseamed together, as exemplified) to and along a work plate 14 of asewing machine 15 (which may be of any well known or suitable type) tobe seamed or otherwise sewn. The sewing machine comprises a needle isfrom which a thread 17 extends, lower and upper looper means (not shown)from which there extend respectively, a lower looper thread 18 and anupper looper thread 1841, a brake 19, a presser foot 29, an upper cutter22, and a lower cutter 23, assembled and operating in a manner Wellknown to the art, and adapted to sew a seam 24 on the fabric when aportion thereof passes the needle, but, when the pair of pieces offabric has passed, to form a strand of unattached sewing extendingbetween the trailing edge of a pair of leading pieces of fabric and theleading edge of a pair of following pieces of fabric. This strand can becut, broken, or otherwise severed at a point rearward of a leading pairof pieces of fabric, but the loose end 25 extending forwardly of thefollowing pair of pieces of fabric needs to be back tacked and(ordinarily also) cut off so that a part 26 of it is attached to thepair of fabric pieces by the subsequent sewing, and any remaining part27 is cut off (and, desirably, disposed of). To this end the exemplifiedapparatus further comprises a swinging arm 30 in the form of a hollowtube having an opening 31 at or near its lower end, and carried on ahollow rotatable member 32 and swingable thereby against the pull of aspring 33 from a stop 34 at a position A, where it can pick up a looseend 25 which extends forwardly of a following piece of fabric, to aposition B wherein it will draw the loose end around an upwardlyextending portion of the thread 17, and across the path of sewing to beformed by the sewing device so as to be back tacked (and, in the presentinstance, to have the portion 27 thereof cut off by the cutters 22 and23). After the arm 3'!) crosses the path of intended sewing, the foot 20is dropped.

As exemplified, there is provided a flexible tube 35 leading to asuction device such as a vacuum pump (not shown) for providing a suctionin the swinging arm 30 for drawing a loose end thereinto when it is inposition A and for yieldably holding the loose end by the suction as thearm swings to position B, so as to draw the loose end across the path offuture sewing and beyond the edge of the fabric, so that sewing by thesewing device thereafter will tie down the loose end by the sewing to beformed along a projected path of sewing on the fabric. In the presentinstance, the portion 27 of the loose end is then cut off by the cutters22 and 23 (at the same time, in the present instance, that they cut thetrim 36 off at the edges of the fabric pieces 11 and 12 beyond the seam)and is sucked up thru the tube 30 for suitable disposal.

The sewing machine is arranged to be started by the movement by theconveyor 10 of a pair of overlying pieces of fabric into the path of alight source PLl of an electric eye FBI, and forms on the fabric a lineof sewing which, in the present instance is the seam 24 forming acontinuation of the part 26 of the loose end 25. When, however, thefabric moves into the path of light to electric eye PE2, the brake 19 isactuated, stop ping the sewing device, and, after a short time-delay,raising the foot 20, which, in turn actuates a lever 38 which, in turn,actuates a limit switch LS which energizes a rotating solenoid 40 whichcauses the arm 30 to swing and to carry the loose end 25 rearward andunder the foot, and then around the needle thread (and, if the needle isdown, the needle itself) and across the intended path of sewing of theseam. When the arm 30 reaches the position B, it contacts a switch LS4which resets the circuit, drops the foot to hold the loose end in place,and releases the brake to start the sewing device up again, andafter theportion 26 of the loose end has been sewn the portion 27 cut otfreturnsthe swinging arm to position A. As soon as it is cut off, the portion 27will be sucked into the hollow swinging arm 30.

In this manner the loose end is back tacked by the succeeding sewing, toproduce the result shown in FIG. 8.

When a pair of overlying pieces of fabric moves into the path of lightto electric eye PE3 from a source above it, it will stop the sewingdevice unless another pair of overlying pieces of fabric has actuatedthe electric eye PEI to override PE3 and continue the operation of thesewing device.

By the exertion of a steady uniform pull on the loose end, either by asuction means as exemplified, or otherwise; the loose end can be pulledto just the degreeof tautness desireda tautness, for example, which willassure easy and effective back tacking, but which will be insufficientto pull up or back or otherwise displace the (right-hand upperFIG. 6)corner of the fabric piece to which the portion 26 of the loose end wasoriginally and still is attached.

As will be seen from FIG. 9, line 115 and line 116 are connected to apower source (not shown). Line 116 connects to line 117 thru a on-oifswitch 117a, and line 117 connects to line 118 thru a protective fuse118a.

Line 118 then connects to a normally closed set of contacts C2A on acoil CR2. The other side of C2A, normally-closed contacts connects inseries to a normally closed set of contacts C4A on a coil CR4 by line119. Line 120 connects the normally closed contacts C4A t0 normally opencontacts PIA on photocell PEI and also normally open contacts C1A on CR1coil in parallel. Line 121 connects to photocell PEI contacts PIB and,in parallel, a set of normally closed contacts P3 on photocell PE3. Line122 connects contacts PIB and P3 to (in parallel) the hold-in coil CR1,one side of the coil M which controls the operating motor (not shown),and an indicating light RA. The other side of CR1 coil, motor coil M,and indicating light RA are connected to line 115.

When coils CR2 and CR4 are deenergized and when contacts PIA are closed,voltage will then flow thru the contacts C2A of CR2 (lines 1I3119), C4Aof CR4 (lines 119420), contacts PIA (lines 120-121), contacts P3 or PIB(lines 121 and 122), to the coil CR1, motor coil, and indicating lightRA. Coil CR1 will then lock itself in thru its own contacts C1A (lines120 and 121) until photocell PE3 is broken, or coils CR2 and CR4 areenergized.

Line 118 then connects to normally open contacts P2 on photocell PEZ;also, in parallel, normally open contacts C2B on CR2. Contacts P2 andC2B are connected in parallel by line 123 to normally closed contacts onCSA time delay coil CR3T D. Line 124 is connected to one side of thecoil of CH2, CR3 time delay coil CR3TD, and an indicating light RB. Theother side of CR2 coil, CR3TD coil, and light RB are connected to line115.

When photocell PE2 is closed, voltage is fed from line 118 thru thecontacts P2, to CR3TD normally closed con- 4 tacts along line 124 to thecoil of CR2, coil of CR3TD, and indicating light RB. CR2 then locksitself in, holding CR3TD and light RB thru its own contacts, (lines 118and 123) until the time on time delay relay runs out, clearing thecircuit thru the normally closed contacts C3A of CR3TD, lines 123 and124. Note that when coil CR2 energizes, it clears the first circuit bymeans of opening lines 118and 119.

When the time on CR3TD is at an end, line 118 is connected to line 125thru normally open contacts C3B on CR3TD. There is also a set of CR4normally open contacts C4B connecting lines 118 and 125. Line 125 goesto the normally closed contacts of LS4. From the normally closedcontacts of LS4, line 126 feeds the coil CR4, the coil F of the footlift, and indicating light RC. The other side of CR4 coil, foot lift,and light are connected to line 115. Connected in parallel to line 118are normally open contacts LS4a and normally open contact C-5B fromwhich a line 127 runs to normally closed contacts C6 from which a line127a runs to coil CR5 and coil CR6TD which are arranged in parallel andconnected to line 115. The contacts C6 are under control of. the coilCR6TD and the contacts CSB are the holding contacts of coil CR5.

Voltage is then fed from line 118 thru the contacts C3B of CR3TD, alongline 125, thru normally closed contacts L4A of switch LS4, along line126 of the coil of CR4, foot lift coil F, and light RC. CR4 then locksin thru its own contacts C4B, lines 118 and 125, keeping the foot liftcoil F energized until limit switch LS4 is actuated by engagement of arm30, opening L4A, opening CR4 contacts C4B and letting the foot pedaldown. The engagement of switch LS4 by swinging arm 30 closes contactsL4B causing voltage to flow from line 118 thru line 127 and normallyclosed contacts C6 of time delay coil CRGTD energizing coils CR5 andCR6TD. The normally open contacts C5B are then closed holding thecircuit in. CR6TD now starts to control a time delay.

Line 118 also connects to limit switch LS5 normally open ocntacts. Thruthese contacts is line 128 to the coil BT of the back tack which is arotating solenoid. The other side of the coil connects to line 115. Theclosing of limit switch LS5 is accomplished by the energizing of thefoot lift coil. In parallel with limit switch LS5 are normally opencontacts C5A controlled by coil CR5. After the timed delay by coilCR6TD, contacts C6 open thus clearing the circuit held in by CSBcontacts. At the same time CSA contacts are closed by CR5 coil. LS5contacts at this stage are open so that, when CSA reopens, theback-tacking coil ET is deenergized permitting the spring 33 to returnthe swinging arm 30 to position A. The circuit is now cleared foranother operation when called for by a photocell PEI, by closing thecontacts C4A of CR4 (lines 119 and Line 118 connects to a normallyclosed set of contacts C1B on CR1, from these contacts line 129 leads tothe brake coil B. The other side of the brake coil is connected to line115. Light RD is in parallel with coil B. The deenergizing of the brakecoil is accomplished by energizing of CR1.

Line 118 is connected to one side of the light sources PLI, PL2, and PL3of photocells PEI, PE2, PE3, the other side being connected to line 115.

Since certain changes may be made in the above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

We claim:

1. Apparatus for back-tacking a loose end formed prior to a sewingoperation of a sewing device; comprising a sewing device, yield'ableloose-end-pulling means movable along a course from a position inproximity to a loose end in advance of said sewing device, back pastsaid sewing device, and across an intended path of sewing on materialbeing sewn; means to move said pulling means along said course after aloose end of sewing has been formed and so as to cross said path after afew stitches have been sewn in the material and While the loose end isyieldably pulled by the pulling means; means to cause further sewingpast a portion of such loose end while the loose end is yieldably pulledby the pulling means whereby the loose end is caught by such furthersewing; and means to return said pulling means to its advance position.

2. Apparatus as in claim 1 wherein said pulling means is arranged toexert on said loose end a pull which is insulficient to cause it to pullout of place the portion of the material to which it is attached.

3. Apparatus as in claim 1 wherein said pulling mean is in the form of asuction means.

4. Apparatus as in claim 1 wherein means are provided for cutting offthe free end of said loose end after the loose end is caught by saidfurther sewing and before the operation of said returning means.

5. Apparatus as in claim 4 wherein means are provided for disposing ofsaid free end after it is cut off.

6. Apparatus for back-tacking a loose end formed prior to a sewingoperation of a sewing machine equipped with a sewing device and withstart means and stop means therefor; comprising a sewing machine havinga sewing device and a start means and a stop means, means to feedmaterial to said sewing device; means to actuate the start means of thesewing machine when a piece of material to be sewn is approaching thesewing device thereof; suction means movable along a course from aposition in proximity to a loose end in advance of the sewing device andthe material to be sewn, past a thread running from the sewing device tothe beginning of a line of sewing on a piece of material, and across theintended path of said line of sewing thereon; means to actuate the stopmeans of the sewing machine after a few stitches have been sewn in thematerial; means to move said suction means along said course after aloose end of sewing has been formed and so as to cross said path afterthe beginning of said line of sewing and while the loose end is heldtaut by the suction means; means to reactuate the start means to causefurther sewing past a portion of such loose end while the loose end isheld taut by the suction means whereby the loose end is caught by thefurther sewing; means to release the operative connection between thesuction means and at least the caught portion of said loose end, meansto return said suction means to its advance position, and means toactuate said stop means after the material has been sewn.

7. Apparatus for back-tacking a loose end formed prior to a sewingoperation of a sewing device; comprising a sewing device, means forreceiving and yieldably pulling a loose end which is in advance of asaid sewing device and for moving the loose end back past said sewingdevice and across the intended path of sewing on material being sewn soas to cross said path after a few stitches have been sewn in thematerial and while the loose end is pulled, said means comprising anelement movable transversely of a portion of said material to cause theloose end to cross said path while it is pulled; and means to causefurther sewing past a portion of such loose end whereby the loose end iscaught by such further sewing.

8. A device as in claim 7 wherein means are provided for determining theextent of stitching of the material prior to the movement of the looseend across the line of stitching.

References Cited UNITED STATES PATENTS 2,313,433 3/1943 Golden 112 -1042,756,704 7/ 1956 Lawber 112254 2,849,974 9/1958 Tishler et al 1l2-254 X2,858,783 11/1958 Lawber 1l2-254 X 2,989,935 7/1961 Butler 1l22523,123,033 3/1964 Weigert 112-197 JORDAN FRANKLIN, Primary Examiner.

J. R. BOLER, Assistant Examiner.

1. APPARATUS FOR BACK-TACKING A LOOSE END FORMED PRIOR TO A SEWINGOPERATION OF A SEWING DEVICE; COMPRISING A SEWING DEVICE, YIELDABLELOOSE-END-PULLING MEANS MOVABLE ALONG A COURSE FROM A POSITION INPROXIMITY TO A LOOSE END IN ADVANCE OF SAID SEWING DEVICE, BACK PASTSAID SEWING DEVICE, AND ACROSS AN INTENDED PATH OF SEWING ON MATERIALBEING SEWN; MEANS TO MOVE SAID PULLING MEANS ALONG SAID COURSE AFTER ALOOSE END OF SEWING HAS BEEN FORMED AND SO AS TO CROSS SAID PATH AFTER AFEW STITCHES HAVE BEEN SEWN IN THE MATERIAL AND WHILE THE LOOSE END ISYIELDABLY PULLED BY THE PULLING MEANS; MEANS TO CAUSE FURTHER SEWINGPAST A PORTION OF SUCH LOOSE END WHILE THE LOOSE END IS YIELDABLY PULLEDBY THE PULLING MEANS WHEREBY THE LOOSE END IS CAUGHT BY SUCH FURTHERSEWING; AND MEANS TO RETURN SAID PULLING MEANS TO ITS ADVANCE POSITION.